QuEst++ is an open source software is aimed at quality estimation (QE) for machine translation. It was developed by Pr Lucia Specia's team at the University of Sheffield and includes contributions from a number of researchers.

It has two main modules: a Java module to extract a number of word, sentence and document-level features and a Python module that interacts with the scikit-learn toolkit for machine learning. Is has also a few python and shell scripts for small things here and there.